1. Field of the Invention
The present invention relates to apparatus and methods useful in the spiral winding and cutting of paper tubes to form composite cans, and in particular, relates to apparatus and methods useful in removing foreign and undesirable materials from the can after the winding and cutting operations.
2. Description of the Prior Art
Numerous prior art patents suggest apparatus and methods for winding a strip of heavy paper into a tube around a mandrel, winding and glueing a labeling strip onto the tube, and then cutting the tube into specified lengths. See, for example, the following U.S. Pat. Nos.: 3,133,483 (Glassey); and 2,712,778 (Robinson).
After the tube is cut into the prescribed length, each length is provided with a bottom, the container is filled with a consumable product (such as concentrated citrus juice, for example) and a removable top is affixed to the open end. This type of container is commonly referred to as a "composite can".
Many millions of such composite cans are required to satisfy the demands of the marketplace. Therefore, the manufacture of these cans must necessarily be accomplished at high production rates. Thus, a typical composite can tube winding machine will manufacture on the order of about one hundred and fifty thousand cans per day.
As described in the above-mentioned patents, it is necessary to provide some means of indexing the cutting operation, in order to insure that each can is cut to the same prescribed length. Some commercially available composite can tube winding machines accomplish this by providing a so-called "trim ring" cutting operation wherein each can is trimmed at one end to insure that each can is of the same length. The result of this operation is a narrow ring of scrap material.
In order to prevent this trim ring scrap from remaining with, or in the can, it is customary to force a high-velocity stream of air across the can following the trimming operation. Nevertheless, an occasional trim ring becomes lodged in the can, and remains there during the closure and sealing operations, to be discovered by the consumer when the can is opened. While the number of such defects is extremely small, on the order of less than 00.2% of manufactured composite cans, the inevitable expressions of consumer concern and concomitant loss of product goodwill represents a substantial economic loss.
There are several prior art patents which suggest techniques for cleaning foreign and undesirable materials from containers during the manufacturing operation.
In U.S. Pat. No. 1,173,255, Eberhart discloses apparatus employing brushes which are moved into the cans in a synchronous fashion.
U.S. Pat. No. 2,262,697 to Pearson discloses a metal can cleaning machine for removing solder in which the cleaning mechanism is aligned with the can and then rotated through the can for cleaning the internal surface.
Other prior art patents of interest include: U.S. Pat. Nos. 3,490,404 (Vanderlaan et al); 2,327,986 (Bach); 3,881,436 (Paumier et al); 3,983,729 (Traczyk et al); 2,295,595 (Gladfelter).